The library idea is, I think, a good one, but as far as I know in order to make your own decals one needs access to an ALPS printer.
I know that there are decal sheets out there for use with 'inkjet' printers but I thought that one of the problems with that idea is that inkjet printers can't print the colour white as they don't have any white ink ( which, I believe, is something one needs to make decals.)
Perhaps I'm wrong here, but I don't know of anyone who has actually made their own decals using anything but an ALPS printer.
Anyone who knows different care to chime in?